Kinematic vs Mechanical Alignment in High Tibial Osteotomy

The Short Term Outcome of Kinematic Versus Mechanichal Alignment After High Tibial Osteotomy for Varus Osteoarthritic Knee : A Prospective Randomized Controlled Trial

To compare between kinematic and mechanichal alignment after High Tibial Osteotomy (clinically and radiologically)

Study Overview

• Status: Not yet recruiting
• Conditions: Genu Varum; Osteo Arthritis of the Knee
• Intervention / Treatment: Procedure: high tibial osteotomy

Detailed Description

High tibial osteotomy (HTO) is a well-established joint-preserving procedure for younger and active patients with medial compartment osteoarthritis associated with varus malalignment. By laterally shifting the mechanical axis of the lower limb, HTO unloads the diseased medial compartment, alleviates pain, and delays the need for knee arthroplasty.

Traditionally, HTO planning has relied on a Mechanical alignment strategy, aiming to shift the weight-bearing line toward the lateral compartment. Fujisawa et al. described targeting a point located at approximately 62-65% of the tibial plateau width, which has been shown to optimize medial compartment unloading and improve long-term survivorship following HTO.

However, mechanical alignment applies a uniform correction target without accounting for individual anatomical variability. This is commonly achieved by correcting varus alignment to a slight valgus position (approximately 3-5°) through increasing the medial proximal tibial angle (MPTA). Such standardized correction may result in overcorrection, increased joint-line obliquity, altered soft-tissue balance, and excessive loading of the lateral compartment. These biomechanical changes may accelerate lateral cartilage degeneration and contribute to postoperative complications, potentially compromising long-term outcomes.

In contrast, Kinematic alignment (KA) is based on restoring the patient's native anatomical alignment and physiological joint-line orientation, rather than forcing all patients toward a fixed valgus target. By correcting only the pathological varus deformity and restoring the MPTA toward physiological values without overcorrection, kinematic alignment aims to preserve normal knee biomechanics and balanced soft-tissue tension.

Accordingly, the present study aims to make HTO not a temporary relief evaluate whether a kinematic alignment strategy in HTO can achieve comparable or superior clinical and radiological outcomes compared with mechanical alignment, while potentially reducing complications and delaying the need for total knee replacement.

• Study Type: Interventional
• Enrollment (Estimated): 100
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: safwat ahmed safwat, resident doctor; Phone Number: +201098444007; Email: safwatahmed46@gmail.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Clinical: 1. Age : Adult with symptomatic osteoarthritic varus knee 2-Medial knee pain with functional limitation ≥6 months despite optimized non-operative care.

Radiological: 1- Medial compartment OA in Xray AP-Lateral view 2-Degree of varus ≥3 and ≤15 degree in long film(full-length, standing hip-to-ankle radiographs) 3-•Varus knee (mpta ≤85 degree and ldfa ≤93 and jlca ≤5)

Physical : 1-Range of motion: Flexion ≥110°, flexion contracture ≤10°, extension lag ≤5°.

2-Gait testing: Able to walk unaided (or with standard aid) for instrumented gait analysis.

Exclusion Criteria:

• 1- Predominantly lateral compartment OA 2- severe patellofemoral arthritis 3- Prior high tibial osteotomy, knee arthroplasty, or complex fracture around the knee 4-Inflammatory arthropathies (eg, rheumatoid arthritis) 5- end stage medial compartment osteoarthritis with bone erosions 6-chondrocalcinosis

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Other: group 1 (mechanical alignment)	Procedure: high tibial osteotomy; High tibial osteotomy (HTO) is a well-established joint-preserving procedure for younger and active patients with medial compartment osteoarthritis associated with varus malalignment. By laterally shifting the mechanical axis of the lower limb, HTO unloads the diseased medial compartment, alleviates pain, and delays the need for knee arthroplasty
Other: group 2 (kinematic alignment)	Procedure: high tibial osteotomy; High tibial osteotomy (HTO) is a well-established joint-preserving procedure for younger and active patients with medial compartment osteoarthritis associated with varus malalignment. By laterally shifting the mechanical axis of the lower limb, HTO unloads the diseased medial compartment, alleviates pain, and delays the need for knee arthroplasty

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
oxford knee score	a validated, patient-reported outcome measure specifically designed for knee pathology. The OKS is a short, patient-centred questionnaire that assesses both pain and functional ability from the patient's perspective. It is widely recognized for its simplicity, reliability, and sensitivity to clinically meaningful changes following knee surgery. By adopting a PROM as the main clinical outcome, this study emphasizes patient-relevant benefit rather than relying solely on radiographic or surrogate measures. The OKS will be assessed preoperatively and at scheduled postoperative follow-up intervals, with the 12-month endpoint defined as the primary time point.	12 months

Secondary Outcome Measures

Outcome Measure	Time Frame
Knee Injury and Osteoarthritis Outcome Score (KOOS)	12 months
University of California Los Angeles (UCLA) Activity Score	12 months

Collaborators and Investigators

• Sponsor: Assiut University

Study record dates

Study Major Dates

• Study Start (Estimated): June 1, 2026
• Primary Completion (Estimated): January 1, 2029
• Study Completion (Estimated): October 1, 2029

Study Registration Dates

• First Submitted: April 19, 2026
• First Submitted That Met QC Criteria: April 19, 2026
• First Posted (Actual): April 24, 2026

Study Record Updates

• Last Update Posted (Actual): May 26, 2026
• Last Update Submitted That Met QC Criteria: May 21, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Bone Diseases; Musculoskeletal Diseases; Genu Varum
• Other Study ID Numbers: High Tibial Osteotomy

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No